How Studying Interactions Between Animal Emotions, Cognition, and Personality Can Contribute to Improve Farm - Genetics and the Behavior of Domestic Animals - page 97

Breeding and genetics has played an important role in such an approach.
Negative emotions and defensive behaviors might be reduced or eliminated
by using genetic stocks that either do not show these behaviors or exhibit
them so little or so infrequently as to be of trivial importance ( Craig and
Swanson, 1994 ). Genetic selection could be a powerful tool for decreasing
the incidence of behaviors associated with welfare problems, such as fear.
Indeed, selective breeding programs for reduced fear or dampened stress
responsiveness have already been established in turkeys ( Brown, 1974 ) and
Japanese quail ( Jones and Satterlee, 1996; Mills and Faure, 1991 ). For exam-
ple, divergent selection of Japanese quail either for short tonic immobility
(TI) fear reactions ( Mills and Faure, 1991 ) or a decreased plasma corticoste-
rone response to restraint ( Jones and Satterlee, 1996 ) led to reductions in
their fear and physiological stress responses to a wide range of potentially
traumatic situations ( Jones and Satterlee, 1996; Mills and Faure, 1991 ).
Likewise, marker-assisted selection may be a useful tool for manipulating
emotional states ( Boissy et al., 2005b ). For example, quantitative trait loci
(QTL) for fear ( Schmutz et al., 2001 ), for reactivity to humans ( Davis and
Denise, 1998 ), and for social reactivity ( Hazard et al., 2012 ) were identified
in cattle and sheep using linked markers. Such linked markers could, in
turn, be used for marker-assisted selection within sire families once the
relationship between the marker and the gene has been determined.
Genomic tools could thus facilitate selection for complex behavioral traits,
which are frequently impossible to measure on a large number of animals.
Identifying and manipulating fundamental behavioral traits that underlie
adaptation to the physical and social farming environment might be an
effective strategy for improving farm animal welfare in a broad sense
as well as safeguarding or enhancing production, product quality, and
profitability.
Some concerns must be addressed before genetic selection is widely
accepted as a welfare-friendly tool. Firstly, as selection for one trait may
also modify other characteristics, it is essential to ensure that there are no
associated undesirable effects on welfare; new breeding tools can indeed
enhance the rate of undesirable change in correlated traits of welfare sig-
nificance ( Rodenburg and Turner, 2012 ). Secondly, it is necessary to take
into account the ethical objections that are raised regarding genetic selec-
tion. However; it is uncertain whether these objections make the distinction
between selective breeding (practiced since animals were first domesticated)
and genetic manipulation (e.g., gene insertion or deletion). Of course, inter-
actions between the animals' genotype and their environment are critical
determinants of animal welfare that may help reconcile production with
ethical concerns ( Boissy et al.,2005b ). Briefly, we regard genetic selection
for reduced fearfulness as ethically sound because it could increase the
animal's ability to interact successfully with its physical and social environ-
ment by dampening the inhibitory effects of fear and alleviating distress.